One of the main objects of the aromatization of foodstuffs for instance is to restore the original quality and nature of the flavor, aroma and taste of a given foodstuff material. Very often in fact the organoleptic properties of foodstuffs particularly diminish or are somehow modified in the course of the processes of freezing and storage, or during the modifications, such as cooking or baking, to which the foodstuffs are subjected in order to yield an edible material.
In the past the aromatization was mainly achieved by using materials of natural origin. Nowadays, however, synthetic chemical compounds are used at an ever increasing rate. Said compounds possess the advantage of being available very often in unlimited quantities and at prices lower than those of the natural materials. Moreover, due to the fact that the flavouring character of a natural material is the result of the overall effect determined by the combination and interaction of each of its constituents, the effects achieved by said natural material are very often not as well reproducible as those obtained by the use of the pure synthetic compounds.
In the field of perfumery the man in the art has to solve a similar problem in attempting to reconstitute the olfactive notes of certain natural essential oils or extracts. The perfumer's creativity however is continually boosted by the finding of new synthetic compounds, the organoleptic properties of which will enable him to introduce unprecedented olfactive characters or nuances into new phantasy perfume compositions.
As a consequence, the problem that the chemical industry has to solve is to satisfy the increasing demand of organoleptically interesting chemicals in order to better suit the specific needs of flavourists and perfumers.
Whereas 2,6,6-trimetyl-1-(but-1-en-3-oyl)-cyclohex-1-en-3-one, a diketo compound of formula ##SPC11##
is known as possessing the typical odour of ionones, reminiscent more particularly of that of violets [see Agr. Biol. Chem. 35, 962 (1971)], we have suprisingly found that 2,6,6-trimethyl-1-(but-2-enoyl)-cyclohex-1-en-3-one, a diketo compound of formula ##SPC12##
possesses an original sweet and fruity odour, reminiscent more precisely of that of pears or apples for example. This particular odour is moreover clearly different from that of the corresponding monoketo derivative, namely 2,6,6-trimethyl-1-(but-2-enoyl)-cyclohex-1-ene, known in the art as ".beta.-damascone", this latter compound possessing a characteristic fruity, minty and slightly harsh odour [see Helv. Chim. Acta 54, 531 (1970)].
Equally different from the odour of .beta.-damascone is the odour of 2,6,6-trimethyl-1-(but-2-enoyl)-cyclohex-1-en-4-ol, a compound of formula ##SPC13##
which develops an original and tenacious fruity and flowery odoriferous note.
Although the odour of the above mentioned compounds of the invention is reminiscent, in some instances, of that of known alicyclic ketones [see e.g. Belgian Patent No. 750049], their olfactory properties are definitely different when the compounds of the invention are used as perfuming ingredients in a perfume composition. This characteristic olfactory effect is well marked in a fruity or a floral perfume composition for example. Whereas .beta.-damascone is particularly appreciated in the art for the reconstruction of the "top-notes" in a synthetic rose oil for example, both 2,6,6-trimethyl-1-(but-2-enoyl)-cyclohex-1-en-3-one and 2,6,6-trimethyl-1-(but-2-enoyl)-cyclohex-1-en-4-ol typically enhance the "background notes" of the said oil, conferring to the thus reconstituted oil an unprecedented harmonious olfactive character.